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Title: Heavy-quark QCD exotica

Authors:
; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1398660
Grant/Contract Number:
FG02-05ER41374
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Progress in Particle and Nuclear Physics
Additional Journal Information:
Journal Volume: 93; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-10-08 15:06:55; Journal ID: ISSN 0146-6410
Publisher:
Elsevier
Country of Publication:
United Kingdom
Language:
English

Citation Formats

Lebed, Richard F., Mitchell, Ryan E., and Swanson, Eric S. Heavy-quark QCD exotica. United Kingdom: N. p., 2017. Web. doi:10.1016/j.ppnp.2016.11.003.
Lebed, Richard F., Mitchell, Ryan E., & Swanson, Eric S. Heavy-quark QCD exotica. United Kingdom. doi:10.1016/j.ppnp.2016.11.003.
Lebed, Richard F., Mitchell, Ryan E., and Swanson, Eric S. Wed . "Heavy-quark QCD exotica". United Kingdom. doi:10.1016/j.ppnp.2016.11.003.
@article{osti_1398660,
title = {Heavy-quark QCD exotica},
author = {Lebed, Richard F. and Mitchell, Ryan E. and Swanson, Eric S.},
abstractNote = {},
doi = {10.1016/j.ppnp.2016.11.003},
journal = {Progress in Particle and Nuclear Physics},
number = C,
volume = 93,
place = {United Kingdom},
year = {Wed Mar 01 00:00:00 EST 2017},
month = {Wed Mar 01 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.ppnp.2016.11.003

Citation Metrics:
Cited by: 28works
Citation information provided by
Web of Science

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  • One of the open questions in non-perturbative QCD has to do with the existence of meson states predicted by the theory other than qq states. These include four-quark states (q{sup 2}q{sup 2} or molecules like KK), states of pure glue (glueballs: gg or ggg) and mixed or hybrid states (qqg). The prima facie candidate for a non-qq state would be one possessing exotic quantum numbers, J{sup PC}, not consistent with a qq combination. Examples include J{sup PC}=0{sup +-},{sup 0--},{sup -+},{hor_ellipsis} Remarkably, states with exotic quantum numbers have not been found despite intensive searches. The case for a possible sighting ofmore » an exotic J{sup Jc}= 1{sup -+} state decaying into {eta}{pi}{sup O}, made a few years ago, seems to be dissolving. Yet, the evidence for non-qq states is clearly present. Conventional qq nonets are over-subscribed, states have been found with decay modes or production characteristics peculiar for qq. The experimental lesson we have learned is that information from a number of complementary processes must be brought together in order to understand the meson spectrum. Information has come from e{sup +}e{sup -},{gamma}{gamma}, {gamma}{gamma}, and pp collisions, from vector meson decays and from peripheral and central hadroproduction. This talk will review the status of the experimental search. I will especially point out how new technology is being brought to bear on the re-visit of the light quark sector. New instrumentation allows for sophisticated and selective triggers. The recent explosion in computing power allows us to analyze data with unprecedented statistics. Preliminary results from a recently completed, ultra-high statistics experiment using the Multiparticle Spectrometer at Brookhaven Lab will be presented. I will also describe the extension of the search to CEBAF, where an approved experiment there will study the sub-structure of scalar mesons via the radiative decays of the ER meson.« less
  • The current theoretical status of hybrids and glueballs is reviewed. The predictions of bag, constituent glue, and flux tube models of these states are compared to QCD sum rule and lattice gauge theory calculations. Current ideas about the decays of hybrids and glueballs are also discussed. {copyright} {ital 1998 American Institute of Physics.}
  • The current theoretical status of hybrids and glueballs is reviewed. The predictions of bag, constituent glue, and flux tube models of these states are compared to QCD sum rule and lattice gauge theory calculations. Current ideas about the decays of hybrids and glueballs are also discussed.
  • We use the classical approximation to the dual QCD field equations to calculate the term in the heavy-quark potential that is proportional to angular momentum squared. This potential combined with potentials obtained in our earlier work gives a result which is esentially the dual of that acting between a monopole-antimonopole pair carrying Dirac electric dipole moments and rotating in a relativistic superconductor. These potentials are used to fit the masses of the low-lying states of the [ital c[bar c]] and [ital b[bar b]] systems. The agreement, achieved with only four parameters, two of which are roughly determined in advance, ismore » better than 1%. We also predict the masses of the lightest [ital c[bar b]] states.« less
  • The large energy and particle densities achieved in relativistic nucleus-nucleus collisions provide an environment conducive to formation of new types of particles or new states of matter. The environment differs from that of high energy elementary particle collisions primarily in the number density of nearest neighbor hadrons and, if a plasma state is formed, nearby quarks and gluons as well. In the chaos of hadronization, new composite particles may emerge. If a plasma has been achieved, free roaming quarks may not locate their color singlet partners and thus may emerge as naked particles. The experimental challenge is to identify thesemore » new particles and states, even though they may be very short-lived, in the presence of the large ``normal`` hadron particle backgrounds. This paper describes some of the most sensitive searches for new particles performed to date and gives the status of some experiments planned for the near future. Although programs at CERN are mentioned, the emphasis is on the programs at the AGS and RHIC. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.« less